Date.prototype.format = function(mask) { 
    var d = this; 
    var zeroize = function (value, length) { 
        if (!length) length = 2; 
        value = String(value); 
        for (var i = 0, zeros = ''; i < (length - value.length); i++) { 
            zeros += '0'; 
        } 
        return zeros + value; 
    };   
    return mask.replace(/"[^"]*"|'[^']*'|\b(?:d{1,4}|m{1,4}|M{1,4}|yy(?:yy)?|([hHMstT])\1?|[lLZ])\b/g, function($0) {
        switch($0) { 
            case 'd':   return d.getDate(); 
            case 'dd':  return zeroize(d.getDate()); 
            case 'ddd': return ['Sun','Mon','Tue','Wed','Thr','Fri','Sat'][d.getDay()]; 
            case 'dddd':    return ['Sunday','Monday','Tuesday','Wednesday','Thursday','Friday','Saturday'][d.getDay()]; 
            case 'M':   return d.getMonth() + 1; 
            case 'MM':  return zeroize(d.getMonth() + 1); 
            case 'MMM': return ['Jan','Feb','Mar','Apr','May','Jun','Jul','Aug','Sep','Oct','Nov','Dec'][d.getMonth()]; 
            case 'MMMM':
            return ['January','February','March','April','May','June','July','August','September','October','November','December'][d.getMonth()]; 
            case 'yy':  return String(d.getFullYear()).substr(2); 
            case 'yyyy':    return d.getFullYear(); 
            case 'h':   return d.getHours() % 12 || 12; 
            case 'hh':  return zeroize(d.getHours() % 12 || 12); 
            case 'H':   return d.getHours(); 
            case 'HH':  return zeroize(d.getHours()); 
            case 'm':   return d.getMinutes(); 
            case 'mm':  return zeroize(d.getMinutes()); 
            case 's':   return d.getSeconds(); 
            case 'ss':  return zeroize(d.getSeconds()); 
            case 'l':   return zeroize(d.getMilliseconds(), 3); 
            case 'L':   var m = d.getMilliseconds(); 
                    if (m > 99) m = Math.round(m / 10); 
                    return zeroize(m); 
            case 'tt': 
                   return d.getHours() < 12 ? 'am' : 'pm'; 
            case 'TT':  return d.getHours() < 12 ? 'AM' : 'PM'; 
            case 'Z':   return d.toUTCString().match(/[A-Z]+$/); 
            // Return quoted strings with the surrounding quotes removed 
            default:    return $0.substr(1, $0.length - 2); 
        } 
    }); 
}